In vivo expression technology and 5' end mapping of the Borrelia burgdorferi transcriptome identify novel RNAs expressed during mammalian infection.
In vivo expression technology and 5' end mapping of the Borrelia burgdorferi transcriptome identify novel RNAs expressed during mammalian infection.
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DOI：
10.1093/nar/gkw1180
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发表时间：
2017-01-25
影响因子：
14.9
通讯作者：
Jewett MW
中科院分区：
文献类型：
--
作者：
Adams PP;Flores Avile C;Popitsch N;Bilusic I;Schroeder R;Lybecker M;Jewett MW
伯氏疏螺旋体是导致莱姆病的细菌病原体，其调节基因表达谱以响应在其蜱-哺乳动物感染周期中遇到的环境。开始描述B的特征。为了在鼠感染期间表达伯氏螺旋体转录组，我们先前采用了基于体内表达技术的方法（BbIVET）。这确定了233个推定的启动子，其中许多映射到复杂的分段基因组的未注释区域。在此，我们全面鉴定了B的5′端转录组。作为验证通过BbIVET发现的非ORF相关启动子的手段。我们证明，119 BbIVET启动子与转录起始位点（TSS）和验证新的RNA转录本使用北方印迹和荧光素酶启动子融合。引人注目的是，49%的BbIVET启动子没有发现与TSS相关。这一发现表明这些序列可能主要在哺乳动物宿主中具有活性。此外，6042 B. burgdorferiTSS揭示了多种RNA，包括许多反义和基因内转录物、无前导RNA、长的非翻译区和用于启动基因内转录的独特核苷酸频率。总的来说，这是B的第一个全面的TSS地图。burgdorferi和表征先前未注释的RNA转录物表达的螺旋体在鼠感染。
Borrelia burgdorferi, the bacterial pathogen responsible for Lyme disease, modulates its gene expression profile in response to the environments encountered throughout its tick-mammal infectious cycle. To begin to characterize the B. burgdorferi transcriptome during murine infection, we previously employed an in vivo expression technology-based approach (BbIVET). This identified 233 putative promoters, many of which mapped to un-annotated regions of the complex, segmented genome. Herein, we globally identify the 5′ end transcriptome of B. burgdorferi grown in culture as a means to validate non-ORF associated promoters discovered through BbIVET. We demonstrate that 119 BbIVET promoters are associated with transcription start sites (TSSs) and validate novel RNA transcripts using Northern blots and luciferase promoter fusions. Strikingly, 49% of BbIVET promoters were not found to associate with TSSs. This finding suggests that these sequences may be primarily active in the mammalian host. Furthermore, characterization of the 6042 B. burgdorferi TSSs reveals a variety of RNAs including numerous antisense and intragenic transcripts, leaderless RNAs, long untranslated regions and a unique nucleotide frequency for initiating intragenic transcription. Collectively, this is the first comprehensive map of TSSs in B. burgdorferi and characterization of previously un-annotated RNA transcripts expressed by the spirochete during murine infection.